Depth mapping with MPI mitigation using reference illumination pattern

2. The apparatus according to claim 1, wherein the illumination assembly comprises a semiconductor substrate, and the first and second emitters comprise semiconductor devices arrayed on the substrate.

3. The apparatus according to claim 2, wherein the first and second emitters comprise vertical-cavity surface-emitting lasers (VCSELs).

4. The apparatus according to claim 2, wherein the illumination assembly comprises a mask, which is formed over the second emitters and configured to restrict the second optical radiation to the second range of angles.

5. The apparatus according to claim 1, wherein the at least one second range of angles comprises two opposing margins of the first range of angles.

6. The apparatus according to claim 1, wherein the processing circuitry is configured to compute first depth coordinates based on the signals output by the sensing elements in response to the first optical radiation and second depth coordinates based on the signals output by the sensing elements in response to the second optical radiation, to detect a discrepancy between the first and second depth coordinates, and to correct the first depth coordinates responsively to the detected discrepancy.

7. The apparatus according to claim 6, wherein the processing circuitry is configured to identify, responsively to the detected discrepancy, an area of the target scene in which the first depth coordinates are distorted due to multi-path interference, and to adjust the first depth coordinates in the identified area so as to compensate for the multi-path interference.

8. The apparatus according to claim 1, wherein the processing circuitry is configured to output a depth map of the target scene including the corrected depth coordinates.

10. The apparatus according to claim 9, wherein the array further comprises at least one row of the second emitters on at least a third side of the central area.

11. The apparatus according to claim 9, wherein the illumination assembly comprises a diffuser having a first zone configured to intercept and diffuse the first optical radiation over the first range of angles, and a zone configured to intercept and diffuse the second optical radiation while limiting the diffused second optical radiation to the at least one second range of angles.

12. The apparatus according to claim 9, wherein the illumination assembly comprises a mask, which is formed over the second emitters and configured to restrict the second optical radiation to the second range of angles.

13. The apparatus according to claim 9, wherein the at least one second range of angles comprises two opposing margins of the first range of angles.

15. The method according to claim 14, wherein directing the first optical radiation comprises driving one or more first emitters to emit the first optical radiation, and directing the second optical radiation comprises driving one or more second emitters configured to emit the second optical radiation.

16. The method according to claim 15, wherein the first and second emitters comprise semiconductor devices arrayed on a substrate.

17. The method according to claim 16, wherein directing the second optical radiation comprises forming a mask over the second emitters so as to restrict the second optical radiation to the second range of angles.

18. The method according to claim 14, wherein the at least one second range of angles comprises two opposing margins of the first range of angles.

19. The method according to claim 14, wherein correcting the first depth coordinates comprises identifying, responsively to the detected discrepancy, an area of the target scene in which the first depth coordinates are distorted due to multi-path interference, and adjusting the first depth coordinates in the identified area so as to compensate for the multi-path interference.

20. The method according to claim 14, wherein processing the signals comprises outputting a depth map of the target scene including the corrected depth coordinates.